At a recording session with my Mark III & 212 cab in the iso room....I take my glasses off when recording & playing live & thought I turned the Treble up, butinstead I turned up the Bass. We spent over an hour wondering where the hell the incredibletone went from the night before.. It was a flabby sounding mess.I changed guitars, cables, cabinets and then noticed I'm a dumb ass & turned the Bass back to its rightful place at 1, with my SG's.

The guy that sold me my first Mark III said, "Dude, keep the Bass down".I didn't listen and sold it 6 months later.

With a Tele or Strat you can boost the bass a bit. Humbuckers seem to like it low.I've owned a Mark I & 3 Mark III's. Still have 2 Mark III's.Mark III's are a sonic masterpiece. Takes a lil' time to dial them in..

I keep the bass knob at 0 to 2, depending on the guitar, and have a stout shallow V shape for the graphic, with the center slider being neutral to preserve more mids. I guess I should call it U shape.

Another absolutely critical item for the MkIII is the treble knob. Sounds great for high gain when set at 8+ (which increases gain), but then you have to back the mega-powerful Presence down to ~3-4, and the clean channel suffers. I reduce my treble knob to 6-7 and have the Presence at 5 and R1 volume at 7.5 and use more Lead Drive to make up for decreasing the treble knob. Even with my EMG 81/85 equipped metal guitars, I can get a full range of good cleans (guitar volume knob reduced) or all-out blistering metal. With passive pickups, the clean sound is truly excellent and of course high gain rules also.

It is a fine art to tune your MkIII to your actual rig, but once it's done, it's a thing of absolute beauty.